Slave server: FATAL: incorrect checksum in control file

Hi Guys,

I'm trying to set up a warm standby server, but have problems with running it on the backup. I feel that I have done like the documentation says:

The WAL is being copied to the slave using rsync.
Doing SELECT pg_start_backup(); (in psql)
Copying the data directory to the slave (using rsync)
Doing SELECT pg_stop_backup(); (in psql)
Making sure the slave is using it's own postgresql.conf and the recovery.conf is set with the pg_standby command.
.
So far I don't get any errors, but when I start postgres on the slave (I'm using pg_ctl), I get the error 'FATAL: incorrect checksum in control file'.

Both servers are running PostgreSQL-8.3.5, configured with exactly the same options (just prefix and ssl).

Any ideas ?

Greetings,

Leif